How does Romans 9 address the issue of Israel's unbelief?

Paul, in Romans 9, addresses the painful topic of Israel's unbelief and their rejection of the Messiah. He indicates that this was foretold by the prophets and aligns with God's sovereign purpose. While a remnant of Israel believes, many do not due to their reliance on works of the law rather than faith. Paul reiterates that God's choice of a people is not based on their ethnic identity but on His mercy. Understanding this helps Christians grasp the unity of God's plan for both Jews and Gentiles, reaffirming that belief comes through faith, not lineage.